Question

我的系统上有HTTParty gem，我可以在rails中使用它。

现在我想独立使用它。

我在尝试：

class Stuff
  include HTTParty
  def self.y
    HTTParty.get('http://www.google.com')
  end 
end
Stuff.y

但我得到

$ ruby test_httparty.rb 
test_httparty.rb:2:in `<class:Stuff>': uninitialized constant Stuff::HTTParty (NameError)
        from test_httparty.rb:1:in `<main>'
07:46:52 durrantm Castle2012 /home/durrantm/Dropnot/_/rails_apps/linker 73845718_get_method
$

Answer 1

您必须require 'httparty'：

require 'httparty'

class Stuff
  include HTTParty
  # ...
end

Answer 2

这完全是因为类

中存在的包含

如果你包含一个带有模块的课程，那就意味着你要带来一个＆＃34;带来＆＃34;模块的方法作为实例方法。

如果您需要更清晰的include和require

我请你参考这个精彩的SO帖子

What is the difference between include and require in Ruby?

以下是我从同一篇文章中取得的一个例子

 module A
   def say
     puts "this is module A"
   end
 end

 class B
   include A
 end

 class C
   extend A
 end
B.say => undefined method 'say' for B:Class

B.new.say => this is module A

C.say => this is module A

C.new.say => undefined method 'say' for C:Class

为什么我得到错误未初始化的常量Stuff :: HTTParty？

2 个答案: